Vinyl acetate-fumaric acid mixed diester copolymer dispersion paint composition

ABSTRACT

Disclosed is a dispersion paint composition prepared by emulsion copolymerization of a monomer mixture consisting essentially of from 20 to 60 weight percent of vinyl acetate and at least 40 to 80 weight percent of a fumaric acid diester from the group of A. AT LEAST ONE FUMARIC ACID DIESTER OF AN ALIPHATIC ALCOHOL WITH FROM 2 TO 8 CARBON ATOMS AND AT LEAST ONE FUMARIC ACID DIESTER OF AN ETHER ALCOHOL HAVING FROM 2 TO 8 CARBON ATOMS; B. A MIXED DIESTER OF AN ALIPHATIC ALCOHOL WITH FROM 2 TO 8 CARBON ATOMS AND AN ETHER ALCOHOL HAVING FROM 2 TO 8 CARBON ATOMS; AND C. A MIXTURE OF (A) AND (B).

United States Patent [191 Fuchs et al.

[4 1 Aug. 26, 1975 [73] Assignee: Deutsche Texaco Aktiengesellschaft,

Hamburg, Germany [22] Filed: July 5, 1973 [2]] Appl. No.: 376,502

[52] US. Cl ..260/29.6 T; 260/296 TA; 260/296 WA; 260/785 B [51] Int. Cl. C08! 45/24 [58] Field of Search 260/296 T, 29.6 R, 78.5 B, 260/296 H [56] References Cited UNITED STATES PATENTS 3,314,908 4/1967 Kagan et al. u 260/296 T 1/1969 Levine et al. 260/296 T 3/1973 Wollner et al. 260/296 T Primary Examinerl-Iarold D. Anderson Attorney, Agent, or Firm-T. H. Whaley; C. G. Ries; Henry W. Archer ABSTRACT Disclosed is a dispersion paint composition prepared by emulsion copolymerization of a monomer mixture consisting essentially of from 20 to 60 weight percent of vinyl acetate and at least 40 to 80 weight percent of a fumaric acid diester from the group of a. at least one fumaric acid diester of an aliphatic alcohol with from 2 to 8 carbon atoms and at least one fumaric acid diester of an ether alcohol having from 2 to 8 carbon atoms; b. a mixed diester of an aliphatic alcohol with from 2 to 8 carbon atoms and an ether alcohol having from 2 to 8 carbon atoms; and c. a mixture of (a) and (b).

2 Claims, No Drawings VINYL ACETATE-FUMARIC ACID MIXED DIESTER COPOLYMER DISPERSION PAINT COMPOSITION The present invention relates to dispersion paint compositions for the production of hard and especially glossy coatings based on vinyl acetate-fumaric acid diester copolymers.

US. Pat. No. 3,720,636 filed in the name of the Applicant herein discloses dispersion paints, the filmforming lacquer component of which is a copolymer produced by reacting a major portion of fumaric acid diesters and minor amounts of vinyl aromatic hydrocarbon, and, optionally, of olefin. These dispersion paints provide coatings which distinguish themselves from the known ones by improved weather resistance, dirtrepellency, light-resistance, and resistance to yellowing.

US. Pat. No. 3,563,944 describes a process according to which vinyl acetate and fumaric acid esters may be emulsion copolymerized to dispersions of a high solids content. Those copolymers containing fumaric acid esters in an amount of up to a maximum of 30 percent are especially suitable for paints. Their filmforming temperature is relatively low, and the lacquers obtained therefrom have good abrasion resistance.

German Patent Application DT-AS 1,093,558 describes the production of dispersions of vinyl acetate copolymers which may contain, among others, up to 40 weight percent of dialkyl fumarates or maleinates. Good freeze stability is indicated as an advantage of such dispersionsv The dispersions, however, give neither glossy nor hard and abrasion-resistant films.

The lacquer films obtained with the known dispersion paints containing fumaric acid diester copolymers are, with respect to their mechanical properties, equivalent to the lacquer films obtained with other known dispersion paints but are less expensive. However, lacquer films of acrylate resins are superior to those of the aforementioned prior art dispersion paints.

The present invention provides a dispersion paint composition which forms coatings having especially high polish and hardness. The lacquer films are equivalent to those obtained by using the expensive acrylate resins. The copolymers have a great capacity to absorb pigments so that they may be used at the same time for the production of highly filled flat finish dispersions. Dispersion paints having a high pigment content are known to give dull coatings. The present invention also provides a process for producing said dispersion paint composition.

The dispersion paint composition according to the present invention comprises a mixture of vinyl acetate and more than 40 weight percent of fumaric acid esters, the ester groups of which are at least partly ether alcohol groups. Preferably, a fumaric acid ester having butoxyethyl groups as the ether alcohol groups is used. Unexpectedly, it has been found in accord with the invention that vinyl acetate-fumaric acid ester dispersions result in films of the desired quality when the pro portion of fumaric acid esters is more than 40 weight percent, preferably more than 60 weight percent, and when at least a portion of the alcohol components of said fumaric acid esters are residues of monoethers of aliphatic alcohols with monoglycols or oligoglycols. Preferably, the ether alcohol component of the fumaric acid ester is the monobutyl ether of ethyleneglycol. The content of said alcohol component preferably should not be below 8 mole percent based on the charged fumaric acid esters.

The process for producing the dispersion paint according to the invention comprises the copolymerisation of the monomer mixture mentioned above in an aqueous emulsion in the presence of at least one emulsifier, optionally in the presence of a stabilizer and a free radical catalyst.

The reaction of the monomers is the more complete, the more nearly the mole ratio of vinyl acetate to fumaric acid esters approaches the value of l l. Accordingly, a monomer mixture of about 25 parts by weight of vinyl acetate, about 25 parts by weight of dibutoxyethyl fumarate, and 50 parts by weight of diisopropyl fumarate gives an especially good dispersion.

Unexpectedly, the introduction of the ether alcohol component gives not only a plasticising effect but, also, an emulsifying effect as well as increases the capacity to take up pigments.

The emulsifying effect is evidenced by the fact that in the polymerization reaction mixture with ether alcohol as the ester component, only 1 weight percent of an anionic emulsifier needs to be added, which is an exceptionally small amount for such polymerization. The lower the amount of emulsifier used, the lower the water sensitivity of the coating.

The incorporation of the ether alcohol component into the polymer may be done by copolymerizing vinyl acetate with a fumaric acid diester of aliphatic alcohols, preferably secondary aliphatic alcohols, and with the fumaric acid diester of ether alcohols. However, also mixed esters of an aliphatic alcohol, preferably a secondary alcohol, and an ether alcohol, or mixtures of the said diester of aliphatic alcohols, the said mixed ester, and the said diester having ether alcohol groups, may be used for the copolymerization with vinyl acetate. Such mixtures are obtained, for instance, by transesterification of fumaric acid diesters with ether alcohols as well as by esterification with mixtures of aliphatic and ether alcohols. As it is technically more convenient to produce mixed ester/diester mixtures from maleic acid anhydride and the alcohol components, costs are minimized by employing such mixturesv The content of ether alcohol groups per se in the polymer affects the quality of the emulsion.

ln a preferred embodiment of the process of the invention, a non-ionic emulsifier is added to the aqueous phase, in addition to the above mentioned anionic emulsifier, in order to polymerize without a stabilizer or a protective colloid (in general, polyvinyl alcohol). With this auxiliary"-combination, the proportion of the anionic emulsifier can be reduced to as low as 0.5 weight percent. Despite the absence of the stabilizer, neither the course of the polymerization itself, nor the useful life and the shear strength of the dispersion obtained are affected. The advantages of this embodiment include the especially high polish of the films and the lowered film-forming temperature. The hardness of the films is not the maximum, but is, nevertheless, within the range of commercial specification for dispersion paints.

The reaction is carried out at atmospheric pressure although other pressure levels may be employed.

The temperature employed is preferably as low as possible but in the range of from to C, The pH value of the aqueous phase shall not be lower than 4.

The invention and the advantages thereof are pres- :nted in the following examples. Examples 1 to 7 are apecific embodiments of the process of the invention. Examples 8 to 10 are comparative examples according .o the prior art.

In Examples 1 to 9. polymerization was accomplished as follows:

The aqueous phase (water with emulsifier. stabiliz- :rs, and one half of the amount of the peroxide catayst) was heated under vigorous stirring with 25 parts y weight of monomer mixture to a temperature of v%()C. After reaching the reaction temperature, the re- Training 75 parts by weight of monomer mixture Iwithin 1 hour) and the other half of the catalyst as a :oncentrated aqueous solution (within hours) were added thereto. The total time at reaction temperature amounted to hours. Thereafter, the reaction mixture was cooled.

EXAMPLE 1 aqueous phase parts by organic phase parts by weight weight H O l02.6 vinyl 20 acetate Na-dodecyl sulfate l.0 dibutoxycthyl l0 fumarate K 5 0 0.5 diisopropyl 70 fumarate NaHCO 0.12

polyvinyl alcohol 1,0

EXAMPLE Z-Mole ratio of vinyl acetate to fumaric acid ester out protective colloid] The example shows the advantage of the absence of a stabilizer or a protective colloid.

aqueous phase parts by organic phase parts by weight weight H. ,O 103.8 vinyl acetate Na-dodccyl sulfate 0.5 dibutoxyethyl 24 fumarate K 3 0, 0.5 diisopropyl 51 fumarate NaHCO- 0,8

non-ionic emulsifier 2.0

EXAMPLE 4 aqueous phase parts by organic phase parts by weight weight H 0 103.0 vinyl acetate 25 Nu-dodecyl sulfate 1.0 dibutoxyethyl 6.1

fumarate K 5 0, 0.5 isopropylbutoxy 29.3

ethyl fumarate NaHt'IO 0.8 diisopropyl 39.6

Continued EXAMPLE 4 aqueous phase parts by organic phase parts by weight weight fumarute polyvinyl alcohol 1.0

EXAMPLE 5 aqueous phase parts by organic phase parts by weight weight H O 103.0 vinyl acetate 25 Na-dodeeyl sulfate 10 diglycolbutyl- 20 ether fumaratc K.,S .O,. 0.5 diisopropyl fumarate l\laI'!Ct'J, 0.8 polyvinyl alcohol 10 EXAMPLE 6 aqueous phase parts by organic phase parts by weight weight H. .O 103.0 vinyl 25 acetate Na-dodecyl sulfate 10 diethoxyethyl 23 fumaratc K. .S. ,O, 0.5 dissopropyl 52 futnarate NaHCQ 0.8 polyainyl alcohol 1.0

EXAMPLE 7 aqueous phase parts by organic phase parts by weight weight H O 102.6 vinyl acetate 20 Na-dodecyl sulfate 1.0 dibutoxyethyl 20 fumuratc K 8 0 0.5 (.liisopropyl fumarate NaHCO- 0.12 polyvinyl alcohol 1.0

EXAMPLE 8 aqueous phase parts by organic phase parts by weight weight H O I083 vinyl acetate 20 Na-dodecyl sulfate 6.0 di-n-octyl 20 fumaratc :0 0.5 diisopropyl 60 fumarate NaHCO; 0.8 polyvinyl alcohol [.0

EXAMPLE 9 aqueous phase parts by organic phase parts by weight weight H 0 1030 vinyl acetate 20 Na-dodecyl sulfate 1.0 din-octy| Z0 fumaratc K 5 0 0.5 diisopropyl 60 fumarate NaHCO 0.

polyvinyl alcohol MPLE (A g In German g v ift -A dulum hardness values according to Koenig (DIN 53 Q 157). To determine the CPVC value (according to aqueous phase pa t by organic phase parts by IND Chem 4] 9% p ge 0). the d sperweight weight sion was pigmented with an increasing concentration of H m ml germ 77 S TiO-,. applied as a film and subsequently coated with a mlwxyulkylcnc dihhm mhcinm 23 high polish alkyd resin lacquer film ofa predetermmate s ycctl thickness of layer. The gloss value of the alkyd resin fig lacquer layer which drops abruptly at the critical pig- 1 2 H ment volume concentration (CPVC) was measured. 4.5 parts by weight thereof were added to said monomers. IL] The fllm-furming properties of the pigmented dispersion were determined when applied to a thickness of 300 microns. Mode 0f Opel-anon fur Example 10 The abrasion resistance was determined according to the TAKD Test Method (Technischer Arbeitskreis Dis- A mixture of 7.7 parts by weight of vinyl acetate 2.3 version (Technical Working Group Dispersion parts by weight of dibutyl maleinate, and 0.45 parts by l969t Test A Pigmented film of a P weight of polyoxyalkylene glycol were added t th cent PVC) having a wet film thickness of 200 microns aqueous phase, which at the beginning contained only is scrubbed by a brush having a total weight of about 0.5 parts by weight of polyoxyalkylene glycol, and 350 grams, a length of 3 inches, and a width of 1.5 under stirring was maintained for 30 minutes at a temwhile p y 1 ml of a l Pemem aqueous perature ranging between 65 and 70C, 69,3 parts b lution of sodium dodecylsulfate per minute on the film, weight of vinyl acetate, 20.7 parts by weight of dibutyl the rush is moved o and fro at a speed of l cycle per fi nate. and 4.05 parts by weight of polyoxyalkylene second. The number of cycles is noted at which an area glycol were then added thereto within it) hours at conof 1 cm is scrubbed off in the middle section of the stant temperature and maintained for 4 more hours at film. More than 5000 cycles have to be resisted for the the reaction temperature. resin to qualify as abrasion resistant". Dispersions The reaction product has the properties indicated in which barely endure 5000 cycles at 60 percent PV Table 1. Owing to the high content of monomer resiare already abrasion resistant at 55 percent PVC.

TABLE I Properties of Dispersions product on sale films or product acc. Viscosity Stability Content of Gloss" Hardness CPVC Film- Abrasion to numbered monomer forming cycles at Examples residues tempera- 60% PVC ture Vinyl acetate medium stable low I0 48 5 Acrylate high stable very low 0 36 80 25 -7500 Fumarate low stable low 40 14 62 -l 2 [000 Example 1 low mostly low 40 still stable" Example 2 low stable very low 62 75 -13 -6000 Example 3 low stable very low 92 BI 7 Example 4 low stable very low 54 38 75 -l0 -6B00 Example 5 low stable very low 52 31 70 -l 5 -420t) Example 6 low stable very low 57 33 75 -l 8 -5000 Example 7 medium stable low 75 24 -7000 Example 8 medium stable low 40 32 t4 -4500 Example 9 coagulated Example 10 medium stable appr. 15% 37 20 8 900 lower limiting value for the dibutoxyethyl fumarate content IDBOF) l0 weight percent based on the total monomer about 5 mole percent 8 mole percent based on lumarates. at which generally, a coagulation is not yet occurring. 'lGloss according to Lange at 45 reflexion and 20 percent PVC. "IHardness after 7 days: 300;.tunpigmented.

dues, the unpigmented film is slightly sticky and its abrasion resistance is not given. although the critical pigment volume concentration (CPVC) of 75 percent is clearly above the pigment volume concentration (PVC) of 60 set for the abrasion test.

The properties of the dispersions obtained according to the Examples and the coatings produced therefrom are illustrated in Table 1 below. in comparison thereto, the properties of three commercial lacquer resin dis persions and of coatings produced therefrom are also given in Table l.

The gloss was measured according to the method of Lange. that is for 20 percent PVC (pigment volume concentration] with an angle of incidence of 45. The values mentioned in Table I under Hardness are pen- What is claimed is:

l. Dispersion paint consisting essentially of the composition prepared by the aqueous emulsion copolymerization of a monomer mixture consisting essentially of from about 20 to 60 weight percent basis monomers of vinyl acetate and at least 40 to weight percent of a fumaric acid diester selected from the group consisting of:

a. at least one fumaric acid diester of a secondary aliphatic alcohol having from 2 to 8 carbon atoms and at least one fumaric acid diester of an ether alcohol having from 2 to 8 carbon atoms selected from the group consisting of dibutoxyethyl fumarate. diethoxyethyl fumarate. isopropylbutoxyethyl fumarate, and diglycolbutylether fumarate;

b. and a mixture of a) and a mixed fumaric acid diester of an aliphatic alcohol having from 2 to 8 carbon atoms; wherein the content of said other alcohol component of said fumaric acid dieslcr is at least 8 mole percent based on the total amount of 

1. DISPERSION PAINT CONSISTING ESSENTIALLY OF THE COMPOSITION PREPARED BY THE AQUEOUS EMULSION COPOLYMEIZATION OF A MONOMER MIXTURE CONSISTING ESENTIALLY OF FROM ABOUT 20 TO 60 WEIGHT PERCENT BASIS MONOMERS OF VINYL ACETATE AND AT LEAST 40 TO 80 WEIGHT PERCENT OF A FUMARIC ACID DIESTER SELECTED FROM THE GROUP CONSISTING OF: A. AT LEAST ONE FUMARIC ACID DIESTER OF A SECONDARY ALIPHATIC ALCOHOL HAVING FROM 2 TO 8 CARBON ATOMS AND AT LEAST ONE FUMARIC ACID DIESTER OF AN ETHER ALCHOL HAVING FROM 2 TO 8 CARBON ATOMS SELECTED FROM THE GROUP CONSISTING OF DIBUTOXYETHYL FUMARATE, DIETHOXYETHYL FUMARATE, ISOPROPYLBUTOXYETHYL FUMARATE, AND DIGLYCOLBUTYLETHER FUMARATE, B. AND A MIXTURE OF (A) AND A MIXED FUMARIC ACID DIESTER OR AN ALIPHATIC ALCOHOL HAVING FROM 2 TO 8 CARBON ATOMS, WHEREIN THE CONTENT OF SAID ETHER ALCOHOL COMPONENT OF SAID FUMARIC ACID DIESTER IS AT LEAST 8 MOLE PERCENT, BASED ON THE TOTAL AMOUNT OF FUMARIC ACID DIESTERS.
 2. Dispersion paint composition according to claim 1, wherein the said fumaric acid diester of a secondary aliphatic alcohol is diisopropyl fumarate. 